diff --git a/src/ytdl_sub/entries/base_entry.py b/src/ytdl_sub/entries/base_entry.py
index f31bbc6f..88d4e19c 100644
--- a/src/ytdl_sub/entries/base_entry.py
+++ b/src/ytdl_sub/entries/base_entry.py
@@ -1,7 +1,6 @@
 from abc import ABC
 from typing import Any
 from typing import Dict
-from typing import Optional
 
 
 class BaseEntry(ABC):
@@ -9,7 +8,7 @@ class BaseEntry(ABC):
     Abstract entry object to represent anything download from ytdl (playlist metadata, media, etc).
     """
 
-    def __init__(self, entry_dict: Dict, working_directory: Optional[str] = None):
+    def __init__(self, entry_dict: Dict, working_directory: str):
         """
         Initialize the entry using ytdl metadata
 
@@ -38,14 +37,5 @@ class BaseEntry(ABC):
         Returns
         -------
         The working directory
-
-        Raises
-        ------
-        ValueError
-            The working directory was never defined in the init
         """
-        if self._working_directory is None:
-            raise ValueError(
-                "Entry working directory is not set when trying to access its download file path"
-            )
         return self._working_directory
diff --git a/src/ytdl_sub/entries/youtube.py b/src/ytdl_sub/entries/youtube.py
index b7e9a86c..5ec6bbdb 100644
--- a/src/ytdl_sub/entries/youtube.py
+++ b/src/ytdl_sub/entries/youtube.py
@@ -1,3 +1,5 @@
+import os.path
+from pathlib import Path
 from typing import Optional
 
 from ytdl_sub.entries.entry import Entry
@@ -9,6 +11,18 @@ class YoutubeVideo(YoutubeVideoVariables, Entry):
     Entry object to represent a Youtube video. Reserved for shared Youtube entry logic.
     """
 
+    @property
+    def ext(self) -> str:
+        """
+        With ffmpeg installed, yt-dlp will sometimes merge the file into an mkv file.
+        This is not reflected in the entry. See if the mkv file exists and return "mkv" if so,
+        otherwise, return the original extension.
+        """
+        mkv_file_path = str(Path(self.working_directory()) / f"{self.uid}.mkv")
+        if os.path.isfile(mkv_file_path):
+            return "mkv"
+        return super().ext
+
 
 class YoutubePlaylistVideo(YoutubeVideo):
     @property
diff --git a/tests/unit/entries/conftest.py b/tests/unit/entries/conftest.py
index 31e1a0d8..101aa81f 100644
--- a/tests/unit/entries/conftest.py
+++ b/tests/unit/entries/conftest.py
@@ -119,7 +119,7 @@ def mock_entry_kwargs(
 
 @pytest.fixture
 def mock_entry(mock_entry_kwargs):
-    return Entry(entry_dict=mock_entry_kwargs)
+    return Entry(entry_dict=mock_entry_kwargs, working_directory=".")
 
 
 @pytest.fixture
diff --git a/tests/unit/entries/test_soundcloud_entries.py b/tests/unit/entries/test_soundcloud_entries.py
index c33d4a51..118b6f3d 100644
--- a/tests/unit/entries/test_soundcloud_entries.py
+++ b/tests/unit/entries/test_soundcloud_entries.py
@@ -58,7 +58,7 @@ def mock_soundcloud_track_kwargs(mock_entry_kwargs, url):
 
 @pytest.fixture
 def mock_soundcloud_track(mock_soundcloud_track_kwargs):
-    return SoundcloudTrack(entry_dict=mock_soundcloud_track_kwargs)
+    return SoundcloudTrack(entry_dict=mock_soundcloud_track_kwargs, working_directory=".")
 
 
 @pytest.fixture
diff --git a/tests/unit/entries/test_youtube_entries.py b/tests/unit/entries/test_youtube_entries.py
index 5335d619..67f7ea79 100644
--- a/tests/unit/entries/test_youtube_entries.py
+++ b/tests/unit/entries/test_youtube_entries.py
@@ -66,7 +66,7 @@ def mock_youtube_video_kwargs(
 
 @pytest.fixture
 def mock_youtube_video(mock_youtube_video_kwargs):
-    return YoutubeVideo(entry_dict=mock_youtube_video_kwargs)
+    return YoutubeVideo(entry_dict=mock_youtube_video_kwargs, working_directory=".")
 
 
 class TestYoutubeVideo(object):